In-feed device and method

ABSTRACT

An improved in-feed device and method for, for example, the final closing stage of a bag filling machine of the type wherein a plurality of bags are filled in a rapid sequence and the bags are subsequently closed. The novel in-feed device is located at the entrance to the bag closing station and includes an in-feed mechanism having a pivoted, movable inlet portion which initially presents open, tapered contact surfaces (FIG. 1) to the entering bar and subsequently, after the bag enters the device, presents closed, parallel contact surfaces (FIG. 2), the contact surfaces continuously moving in a longitudinal direction along the machine. The inlet portion, made up of two pivot arms, is moved from its tapered configuration to its parallel configuration and back again for each bag by means of a horizontally disposed yoke having diverging, slotted arms and being driven by a single centrally located, in-line air cylinder. Vertical pins fixed to the pivot arms and riding in the slots of the diverging yoke arms, cause the pivots arms to move in and out as the yoke is reciprocally driven by the air cylinder. The longitudinally moving contact surfaces, formed by moving belts, position, hold and guide the top of the bag (whose gussets have previously been reformed after the bag has been filled) preliminarily to its being closed by heat sealing or, alternatively, by sewing. Retarding finger straps are included at the inlet portion to initially apply pressure to certain types of bags to prevent the formation of wrinkles therein.

United States Patent Harris et al.

[ 1 lN-FEED DEVICE AND METHOD [75] Inventors: Thomas Charles Harris,Monroe;

Doyle Rayford Hudson, West Monroe, both of La.

[73] Assignee: Olinkraft, Inc., West Monroe. La.

[22] Filed: Oct. 23. 1973 [2i] Appl. No.: 408.310

[52] U.S. Cl 53/44; 53/371 [51] Int. Cl B65b 7/06 [58] Field 01' Search53/39. 38, 40. I88, 44, 53/139. 371, 372, 373

[56] References Cited UNITED STATES PATENTS 2.097.447 ll/l937 Cundall etal. 53/371 X 2.362.462 l 1/1944 Belcher et ul 53/139 X 2.725.168 11/1955Lindstaedt Et L11. 53/188 3.236.433 11/1966 Johnson et al 53/373 X3.420.034 H1969 Saraisky et a1 53/372 X 3.559.372 2/1971 Cerioni 53/37lX [57] ABSTRACT An improved in-feed device and method for, for ex- Apr.8, 1975 ample, the final closing stage of a bag filling machine of thetype wherein a plurality of bags are filled in a rapid sequence and thebags are subsequently closed. The novel in-feed device is located at theentrance to the bag closing station and includes an in-feed mechanismhaving a pivoted, movable inlet portion which initially presents open,tapered contact surfaces (FIG. 1 to the entering bar and subsequently.after the bag enters the device. presents closed, parallel contactsurfaces (FIG. 2), the contact surfaces continuously moving in alongitudinal direction along the machine. The inlet portion. made up oftwo pivot arms. is moved from its tapered configuration to its parallelconfiguration and back again for each bag by means of a horizontallydisposed yoke having diverging. slotted arms and being driven by asingle centrally located. in-line air cylinder. Vertical pins fixed tothe pivot arms and riding in the slots of the diverging yoke arms, causethe pivots arms to move in and out as the yoke is reciprocally driven bythe air cylinder. The longitudinally moving contact surfaces, formed bymoving belts. position, hold and guide the top of the bag (whose gussetshave previously been reformed after the bag has been filled)preliminarily to its being closed by heat sealing or. alternatively, bysewing. Retarding finger straps are included at the inlet portion toinitially apply pressure to certain types of bags to prevent theformation of wrinkles therein.

12 Claims, 4 Drawing Figures PATENTEDAPR 8l975 SHEET 1 or 4 PATENTEUAPR'3x915 3,875,726

saw u g g m? Iwmlllm: I

lN-FEED DEVICE AND METHOD CROSS-REFERENCES TO RELATED APPLICATIONS US.Pat. No. 3.698.45l. issued Oct. l7. l972 (filed Feb. 8, I97 I to DoyleR. Hudson and entitled Automatic Bag Opening and Filling Apparatus.

U.S. Pat. No. 3,750,72l, issued Aug. 7. I973 (filed Aug. [8, 1971) toDoyle R. Hudson and entitled Expanding Fill Spout for Bag FillingMachine.

U.S. Pat. No. 3.755.986. issued Sept. 4. I973, (filed Sept. 30. 1971 toDoyle R. Hudson and entitled Gusset Reformer.

U.S. Pat. No. 3.796.300. issued Mar. 12. I974 (filed July 17. l972)toDoyle R. Hudson and entitled Multiple Finger Pushers.

Patent application Ser. No. 344.l20. filed July 10, I973 by Doyle R.Hudson and entitled Drop-Down Fill Spout For Bag Filling Machine.

The foregoing related patents and patent application are all assigned toOlinkraft, Inc.. the assignee of the present application. and aredirected to various elements or sections of a fully automatic fillingmachine for bags including the bag opening, filling, moving andreforming portions thereof; while the preferred embodiment of thepresent invention is directed to the infeed device used in the finalclosing and sealing portion of the machine.

BACKGROUND OF THE INVENTION The present invention relates to an in-feeddevice and method for grasping, positioning and guiding a structurecomprised of two facing sheets of flat material. as for example the topofa bag, as it is being introduced into a machine, as for example a bagclosing station utilizing sewing or heat sealing means. The presentinvention has been found to be particularly useful in the bag handlingart. especially as the mechanism for transferring the bag from a bagreforming station to the final bag closing station. and hence will bediscussed with particular reference thereto.

Several types of in-feed devices and methods have been known and usedbefore. and typical examples thereof in the bag handling art are shownin U.S. Pat. No. 3,687.790, issued Aug. 29. I972 to T. Wehren et a], andU.S. Pat. No. 3,69l,968, issued Sept. 19. I972 to Schnepf, U.S. Pat. No.2,097.447, issued Nov. 2. I937 to Cundall et a], and U.S. Pat. No.2,725,168. issued Nov. 29, 1955 to Lindstaedt et al. The Wehren infeeddevice. as shown particularly in FIGS. 2 and 3, constitutes a dual.opposing set of parallel belts moving in a longitudinal direction. thebelts being run around supports which are static or fixed inrelationship to one another and hence cause the belts to remain parallelat all times during operation. The Schnepf in-feed device, as shownparticularly in FIG. 2, utilizes a dual, opposing set of moving beltswhich at its inlet portion have a tapered or slanted or diagonaldisposition before becoming parallel. but whose supports remain staticthroughout operation insofar as their relative positions are concernedand hence the belts follow the same path throughout the machine'soperation. The Cundall infeed device. noting particularly FIGS. 3 and 4,includes dual, opposed moving belts mounted on rollers carried onopposing swinging supports which move from a closed. paralleldisposition to an open. diagonal disposition and back again, but whosesupport rollers ae all equal in diameter and hence the moving belts donot have a tapered entry when closed.

However, it has been found that the bags in being processed through thein-feed devices of the prior art often or at least on occasion becamemisaligned or wrinkled, so that when they were closed in the sewing orsealing station, the closures were improperly and/or inaccurately madeor made askew. It is further noted that a Wehren type device. that is.one in which the bag is fed in between static rails with parallelconveyor belts. does not work reliably. Moreover. as the the Schnepfdevice. that is, one in which the bag is fed initially into a taperedbut fixed inlet and then through static. parallel conveyors. although itdoes work better. it still suffers from the problems referred to above.Indeed a special operator was often needed in the prior art to performmanual or hand feeding of the bags to the closing station. Finally, asto the Cundall and Lindstaedt devices. although in using pivotingsupport arms they may have worked still better, they. it is believed.suffer from at least some of the same problems referred to above.

In contrast to the prior art. the present invention utilizes an in-feedmechanism utilizing not only dual, opposed. moving belts whose supportsare not static but instead, initially present a tapered configuration atthe inlet portion as the bag enters it and subsequently. after the bagenters the device. presents in part a closed. parallel configuration asthe supports are pivoted together. but also includes a slightly taperedportion at its distal end even when the supports are pivoted together.Thus. dual pivot supports or arms movable in and out into and away fromthe center-line of the machine are utilized in combination withlongitudinally moving contact belts on the relatively moving pivotsupports to initially present an open, tapered inlet configuration andthereafter to present a closed. parallel configuration but still havinga slightly tapered distal portion. Such a combination causes the movingbelts to initially but positively contact the bag with a point contactand then later. in a continuous. smooth flowing fashion. contact the bagwith full line, face-to-face engagement. This combined. staged actionallows the in-feed device to properly guide, align and hold the bag inpreparation for the closing operation.

Additionally. retarding pressure fingers are positioned in the frontentry portion of the device which bear against the bag at a pointremoved from the initial contact point with the belts. The pressurefingers serve to retard the bag. removing any wrinkles or preventing theformation of any wrinkles.

The staged (point to line) but positive contact action of the belts onthe movable pivot arms and the pressure retarding action of the fingersacting in combination on the bag eliminate all the problems of the priorart. However. it should be noted that. although the combined action isbelieved to be synergistic or at least preferred. the two mechanisms canoperate independently of one another and have independent value.

Furthermore. the present invention provides the solution to the priorart problems with a straight-forward, reliable and relatively simpledevice without any need for hand labor.

Additionally, as explained more fully below, besides serving as a simplein-feed device, the present invention can also be used to perform thefinal reforming step for the gusseted bag top, eliminating the structureheretofore used for that step.

Finally, the in-feeding operation is performed without the need of doingit at an unreasonably high speed because of combining the finalreforming, in-feeding and initially closing functions in a singleoperation, further enhancing the reliability of performance.

BRIEF DESCRIPTION OF THE DRAWINGS For a further understanding of thenature and objects of the present invention, reference should be had tothe following detailed description, taken in conjunction with theaccompanying drawings, in which like parts are given like referencenumerals and wherein:

FIG. I is a top, plan view of the preferred embodiment of the in-feeddevice of the present invention, showing the inlet portion thereof inits open, tapered disposition, with the bag just beginning to enter intothe in-feed device; while FIG. 2 is a top, plan view of the preferredembodiment of the in-feed device of the present invention with the inletportion in its closed, parallel disposition, with the bag almost fullyinto the in-feed device.

FIG. 3 is a side, partial view of the preferred embodiment with theinlet portion being in its closed configuration, as illustrated in FIG.2.

FIG. 4 is an end. cross-sectional view of the preferred embodiment,taken along section lines 4-4 of FIG. 3.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Introduction Thein-feed device of the present invention can be utilized as the in-feeddevice for any sort of bag opera tion station wherein it is importantthat wrinkles not be present in the top of the bag and the top of thebag be properly aligned and positioned as it is being operated on. orfor that matter for other types of structures which include two sheetsof flat material in face-toface engagement wherein their relativealignment is important. A particularly important area of application ofthe present invention is in the in-feed portion of the bag closurestation which forms the final step of reestablishing the preformedgussets in a paper bag after it has been filled, and therefore thepreferred embodiment of the present invention will be described withrespect to such an application. Also. the present invention isespecially suitable for use with the pinch style bag and the preferredembodiment will be described with respect thereto, but the presentinvention could be applied to almost any bag where the elimination ofwrinkles in the closure area and the proper positioning of the bag areimportant. In the preferred application of the present invention, thefinal closure of the pinch Style bag is accomplished through thereactivation of a pre-applied hot melt and the folding over and securingof a top flap which is manufactured on the bag itself and the preferredembodiment will be described with respect thereto, but the presentinvention is of course equally applicable to the closing of a bag by othmeans such as for example a sewing process.

As generally referred to in the Cross-References to RelatedApplications" supra. the preferred embodiment ofthe present invention isused in a bag filling machine in the very final step of reestablishingthe preformed gussets in the paper bag after it has been filled andprior to it being sealed or sewn closed. For a general understanding ofthe relationship of the final closing station, with the in-feed deviceof the present invention, to the other stations which preceed it in thefully automatic bag filling machine of which it is a part, reference ishad to U.S. Pat. No. 3,755,986 entitled Gusset Reformer, andparticularly to its FIG. 1 and its column 3, lines I9-50. In theover-all machine, a bag to be filled is first opened, filled and thenreformed, all as it is being conveyed down the machine. Finally, withthe use of the in-feed device of the present invention, the bag is movedfrom the bag reforming station to the closing station for final sealingor sewing. The prime function of the in-feed device and method of thepresent invention is to grasp, guide and hold the top of the reformedbag top and properly position it for final closing. Secondarily itserves as the final reforming element for the bag top by bringingtogether in face-to-face engagement the reformed gussets and the faceand back of the bag.

STRUCTURE & ITS METHOD OF USE With reference particularly to FIGS. 1 and2, the preferred embodiment of the in-feed device of the presentinvention includes two pivoted, opposed, in-feed arms 1 and 2, whichpivot about axes 3 and 4, respectively. The in-feed pivot arms 1 and 2are driven from their open/tapered disposition (FIG. 1) to theirclosed/parallel disposition (FIG. 2) and back again by means of areciprocating yoke 5 driven by air cylinder 6.

The yoke 5 has two diverging arms 7 and 8 with slots 9 and 10 therein.Vertical pins II and 12 are fixedly attached to the pivot arms 1, 2 andride in the slots 9, 10. The yoke 5 and the air cylinder 6, which areconnected together by drive arm 13, are positioned horizontally in-line,along the center-line of the machine. Guide arm 14 serves to keep theyoke 5 in proper horizontal and lateral alignment as the yoke assemblymoves longitudinally under the action of the air cylinder 6. As aircylinder 6 causes the yoke assembly to reciprocate forward (to the rightin FIG. 1) and back (to the left in FIG. 2) in a longitudinal direction,vertical pins 11 and 12 riding in yoke slots 9, 10 cause the pivot arms1, 2 to go from the open, tapered, inlet disposition of FIG. I to theclosed, parallel, holding disposition of FIG. 2 and back open again.

The pivot arms I, 2 carry dual, opposed conveyor belts l5 and 16,respectively, which provide moving contact surfaces for holding the topsof the bags as they are conveyed to the closing station. The belts l5,16, which are rubber V-belts, are endless and are each mounted on threevertically disposed rollers 17-19 and 20-22, respectively. The verticalaxes of rotation of the back, exit rollers 17, 20, of the centralrollers 18, 21 and of the front, entry rollers 19, 22 are fixedlymounted on the pivot arms I, 2, respectively, and are in-line with eachother on each arm.

However, in the most preferred embodiment the diameters of the entryrollers 19, 22 are a little less than that of the other rollers so that,although the belts l5, l6 are substantially parallel to each other inthe closed disposition of the pivot arms I, 2 (FIG. 2) as they contactthe bags, there is still a slight entry taper or gap in the forward,entry portion. This gap allows room for retarding finger straps 23 and24 to contact the bag at the entry portion of the device to applyretarding pressure toward the rear of the bag which tends to stretch thetop of the bag and eliminate any wrinkling that may occur when the sides(face and back) of the top of the bag are forced together by the belts15, 16. The retarding finger straps 23, 24 are made of resilient,springy material and are so mounted on the front, curved inlet portions25, 26, respectively, of the device that they have an inherent tendencyor bias to move away from the bag or outwardly toward the sides of themachines so as to bear against the tips of adjusting or set screws 27and 28. The adjusting screws 27, 28 adjust the pressure applied on thebags and, when fully backed off, eliminate the retarding action as thefinger straps 23, 24 will then lay flat against the sides of the pivotarm extensions 29, 30 out of contact with the bags. The retarding fingerstraps 23, 24 need not be used with all types of bags, but should beused with those bags that are relatively flimsy with a substantialtendency to wrinkle.

The pivot arm extensions 29, 30 and the horizontal support plates 31 and32 are fixedly attached to the pivot posts 33 and 34, and all movetogether and form the pivot arms 1, 2. The vertical pins 11, 12 aremounted on and attached to the pivot posts 33, 34, respectively, bymeans of brackets 35 and 36. The brackets 35, 36 are longitudinallyadjustable with respect to the pivot posts 33, 34 by means of adjustingslots 37 and 38 included therein and the co-operating locking screws 39and 40, and 41 and 42. (It is noted that the adjusting slots in pivotpost 34 can not be seen in the figures but are substantially identicalto slots 37, 38.)

The pivot arm extensions 29, 30 are made of channel iron and presentopposing flat surfaces (note FIG. 4) to each other when the pivot arms1, 2 are closed. These flat surfaces are of course static when the pivotarms 1, 2 are closed and serve to further but only generally guide andposition the top of the bag as the bag is moved through the in-feeddevice and into the closing station. In contrast to the static flatsurfaces of the pivot arm extensions 29, 30 with only little or lightcontact with the bag top, the belts l5, l6 serve as moving contactsurfaces in full face-to-face, compressive engagement with the bag top.

At the exit end of the belts 15, 16 at the back, exit rollers 17, 20,there is included a second set of contact belts 43 and 44 mounted onsupports which are static or fixed with respect to one another duringoperation. These parallel feed belts 43, 44 are in contact with the bagtop as it moves through the closing station (not specifically shown).

The bag as it approaches the in-feed device is supported on a staticsupport pan 45 (identical to the trough-shaped plate of FIG. 1 of theHudson 986 patent) and is being pushed forward in cycles by means of themultiple finger pushers 46 (shown in phantom line in FIGS. I3 and whichare the subject matter of the Hudson 300 patent).

As best shown in FIG. 3, the bag is pushed on to the horizontallydisposed conveyor belt 47 which supports the bag and conveys it into thein-feed device and through the closing station. The belts 15, 16 and 43,44 all move at the same linear speed as the conveyor belt 47 andmaintain a griping contact pressure on the top of the bag as it is movedand supported by the bottom conveyor 47 through the in-feed device andclosing station.

As generally shown in FIGS. 1 and 2, the bag is pushed by the multiplefinger pushers 46 down the support tray 45 into the throat or entry ofthe in-feed device, while it is in its open, tapered disposition. In theactual position of the multiple finger pushers 46 illustrated in FIG. 1,the pushers 46 are in the position of being longitudinally retractedback (to the right in the figure) to begin a new pushing cycle, andreference should be had to the Hudson 300 patent for a furtherunderstanding of this operation.

At the point the bag is in the position shown in FIGS. 2 and 3, themultiple finger pushers 46 have reached their extreme forward position(to the left in the figures), leaving the bag partially on the tray 45and partially on the bottom conveyor 47. At this point the air cylinder6 is actuated through line 48 to close the pivot arms 1, 2 by means ofthe yoke/pin assembly 5/] l-l2 to the parallel disposition shown in FIG.2. As best seen in FIG. 2, when the pivot arms 1, 2 close. the leadingedge of the bag is between the two central rollers 18, 2I, the belts 15,16 are in griping contact with the bag top, and the retarding fingerstraps 23, 24 are applying retarding pressure to the central portions ofthe bag top. The co-operative action which is produced on the bag by themoving belts 15, 16, the static finger straps 23, 24 and the bottomconveyor 47 prevents any wrinkles from occurring in the bag top andproperly posi tions and aligns the bag top for closing. It should befurther noted that the initial contact between the belts l5, l6 and thebag top is a point contact (because of the pivoting action) rather thanan immediate face-to-face contact and that this point contact occurs ator in close proximity to the leasing edge of the bag. With the pivotarms 1, 2 closed and the bag being conveyed by the bottom conveyor 47,the initial point contact then in a continuous manner becomes a fullline, face-to-face contact throughout the bag length. This action playsan important role in the superior results achieved by the presentinvention.

After the pivot arms 1, 2 close and the conveyor belt 47 moves the bagthrough the in-feed device and into the closing station where the belts43, 44 are then in contact with the bag top, the pivot arms 1, 2 arereopened by the air cylinder 6 being actuated through air line 49. Inthe meantime, multiple finger pushers 46 have retracted, engaged thenext bag, and moved back again to its most forward position, bringinganother bag into the throat or entry of the in-feed device, and thecycle is repeated.

It should be noted that with the preferred embodiment of the in-feeddevice, the bag gusset reformer (such as the one which is the subjectmatter of the Hudson "986 patent) can be operating on the bag in reforming the bag gussets right up to its entry into the in-feed device.Indeed, the infeed device can serve as the final element in thereforming operation by bringing together the gussets (which have beenreformed) and the face and the back of the bag when the pivot arms 1, 2are closed and the top of the bag is passed through the parallel contactportions of the moving belts 15, 16. Thus the in-feed device of thepresent invention can be substituted for the guide rail holding means(enumerated as element 30 in the Hudson 986 patent). Indeed, with such apreferred substitution, an over-all superior closing operation isachieved. The gradual closing of the bag (with an adequate amount of bagmaterial above the bag fill line of the product) and sufficient timeprovided for the work to be done upon the upper portion of the bag bythe various components of these devices enhances the uniform wrinklefree closure obtained with the use of the present invention.

In summary then, in the present invention, the bag is fed from staticrails and supports to a movable tapered in feed conveyor wherein theconveyors grab the bag in a point contact when the bag is about one-halfinto the in-feed device. When the transfer is made to the closed,parallel conveyors and a bag is about one-third into the fixed, parallelconveyors for the closing station. the pivot arms open up to accept thenext bag. It is noted that in the preferred embodiment illustrated thebags are approximately l inches apart. moving at about 32 feet perminute. and the bags have a face width of approximately 16 inches and aheight of approximately 24 inches and are to be sealed with a plasticresin by being passed through a heating element in the closing station.Thus. in the present invention. the in-feed device grasps a leadingportion of the bag with tapered. pivotable conveyor belts while thebottom of the bag is being moved on a moving bottom conveyor off thedead plate. and finally completely closes the bag after the pivot armsclose and the bag is passed through the in-feed device.

Although the mechanism described in detail supra has found to be mostsatisfactory and preferred. many variations in its structure are ofcourse possible. For example. rather than use the single air cylinder 6and yoke/pin assembly /1 ll 2. two separate opposed. diagonally disposedair cylinders could be used. one on each pivot arm. Also. because thebelts 15. 16 do not come into contact with the bag until the belts passover the central rollers 18, 21 the lead or entry rollers 19, 22 couldbe positioned further back on the support plates 31, 32 closer to thecentral rollers 18, 21. Indeed. the entry rollers conceivably could beeliminated. but their presence produces a better. more graduated taperor angular contact in the initial contact between the belts and the bag.Additionally, other detailed mechanisms can be added to the in-feeddevice. such as for example a belt tensioning system. etc. Moreover. itis conceivable that one of the pivot arms could be static or fixed whilethe other one is the only one that is moved or pivoted to present theopen and closed configurations. and such an approach. althoughconsidered inferior. would be within the broadest concept of the presentinvention as an equivalent variation.

The above are of course merely exemplary of the possible changes orvariations.

Because many varying and different embodiments may be made within thescope of the inventive concept herein taught. and because manymodifications may be made in the embodiment herein detailed inaccordance with the descriptive requirements of the law, it is to beunderstood that the details herein are to be interpreted as illustrativeand not in a limiting sense.

We claim:

1. An in-feed device for a machine for structures comprised of facingsheets of flat. flexible material which need to be properly aligned forfurther processing. such as for example the top of a bag needing to beclosed. comprising:

a basic machine support structure;

two. opposed. elongated pivot arms pivotably mounted on said supportstructure for pivoting about axes which are located on opposite sidesof. but in proximity to, the center-line of the machine;

drive means mounted on said support structure for pivoting said pivotarms about said axes from a closed disposition wherein said pivot armsare parallel to said centerline to an open disposition wherein saidpivot arms are diagonal to said centerline and back again;

moving means mounted on each one of said pivot arms for providing movingcontact surfaces on the inner sides of said pivot arms. said movingcontact surfaces being at least in substantial part parallel and inopposing face-to-face relationship to each other when said pivot armsare parallel and presenting a tapered or angular disposition when saidpivot arms are diagonal;

conveyor means for conveying the structures on a one-by-one basis intothe distal ends of said pivot arms removed from said axes;

control means for actuating said drive means to dispose said pivot armsin their open disposition for entry of each structure and to disposesaid pivot arms in their closed disposition when each structure issubstantially into and between the open pivot arms; whereby, when saidpivot arms are driven to their closed disposition, the contact surfacesinitially contact the structure with point contact and then will fullline. face-to-face contact as the structure is conveyed through thein-feed device; and

opposed retarding pressure finger means mounted on said distal entryends projecting inwardly toward said center-line and angularly backtoward the proximal ends of said pivot arms to a point intermediate tosaid distal and said proximal ends for bearing against the structureonly at points removed from the initial Contact point of the movingsurfaces with the structure when said pivot arms are in their closeddisposition for retarding the immediate and following portions of thestructure against the advancing force of the contact surfaces in Contactwith the structure; whereby wrinkles in the material are eliminated orprevented from formingv 2. The device of claim 1 wherein said pivotarms. when in their closed disposition, are parallel to each other alonga first facing portion and then diverge slightly from one another attheir distal entry ends forming a gap there between; thereby forming atapered entry portion even when said pivot arms are in their closeddisposition.

3. The device of claim 1 wherein said pressure finger means are made ofstraps of resilient. springy material and have inherent bias to moveaway from said centerline, and wherein there is further included:

set screw adjusting means mounted on said pivot arms and bearing againstthe operative ends of said straps for adjusting the physical location ofthe dista]. operative ends of said straps with respect to saidcenter-line; whereby the retarding pressure of the straps can be variedor the straps moved away from the center-line to such an extent that thestraps are rendered inoperative.

4. The device of claim 1 wherein said moving contact surfaces are belts.each one mounted on at least two rollers attached to the pivot arm.

5. The device of claim 1 wherein there is included at least threerollers an entry roller located toward the distal end of each said pivotarms. a central roller located centrally on each said pivot arms. and anexit roller located toward the proximal end of each said pivot arms,said entry roller having a diameter less than that of the other tworollers which are equal. whereby, when the contact surfaces becomeparallel between said cen tral and exit rollers when said pivot arms areparallel. the contact surfaces as they approach the central rollers doso with a relatively gradual taper.

6. The device of claim 1 wherein there is further included:

bottom conveying means associated with said con veyor means forsupporting and conveying the structure through the in-feed device andinto the next processing station of the machine.

7. The device of claim 1 wherein there is further included:

a supplemental. opposed set of parallel. moving contact surfaces mountedon supports which are fixed with respect to one another during operationand which bridge between the proximal ends of said pivot arms and thenext processing station of the machine. the exit portion of said movingbelt means leading into said supplemental set of moving contactsurfaces.

8. The method of feeding structures on a one-by-one basis into a machinewherein the structures are comprised of facing sheets of flat, flexiblematerial which need to be properly aligned for further processing, suchas for example the top of a bag needing to be closed, comprising thefollowing steps:

a. providing an in-feed device having an inlet portion comprised of twomovable, opposed support arms mounted on opposite sides of thecenter-line of the machine and carrying on their inward, opposed sideslongitudinally moving contact surfaces, and also carrying on theirinward. opposed sides pressure finger means located at the distal. entryends of said support arms and projecting inwardly toward saidcenter-line and angularly back toward the proximal ends of said supportarms to a point intermediate to said distal and said proximal ends, saidsupport arms initially having an open, angular disposition with respectto the center-line of the machine, and providing appropriate conveyingmeans in association with said in-feed device;

b. conveying the structures into the inlet portion of the in-feed deviceso that the leading edge of said structure is past the ends of saidpressure fingers and the structure is substantially into and betweensaid opposed support arms;

c. positively grasping the leading edge of the structure with thelongitudinally moving contact surfaces by moving the support structuresangularly in from their initial, open. angular disposition and towardthe center-line of the machine so that the contact surfaces initiallystrike the leading edge of the structure at an angle with only opposed.point contacts. and closing at least an opposed portion of the supportstructures together so that the moving contact surfaces come togetherafter initially striking the structures changing the point contacts tocontinuing. face-to-face, in line and opposed contacts;

(1. conveying the structure through the in-feed device to the nextprocessing station of the machine; and

e. applying a retarding force on the structure by means of said pressurefinger means bearing against only the intermediate portions, at an arealocated between the distal and proximal ends of said support arms, andsubsequentially the trailing edges of the structure in a directionopposite to the advancing action of the conveying means while thestructure is being conveyed through the in-feed device; whereby wrinklesare removed from, or prevented from forming in, the material. 9. Anin-feed device for a machine for structures comprised of facing sheetsof flat, flexible material which need to be properly aligned for furtherprocessing, such as for example the top of a bag needing to be closed,comprising:

a basic machine support structure; two. opposed. elongated pivot armspivotably mounted on said support structure for pivoting about axeswhich are located on opposite sides of. but in proximity to. thecenter-line of the machine, each said pivot arms including at leastthree roller sections, an entry roller section located toward the distalend of each said pivotal arms. a central roller section locatedcentrally on each said pivot arms. and an exit roller section locatedtoward the proximal end of each said pivot arms, said entry rollersection having a diameter or width less than that of the other tworoller sections which are equal;

drive means mounted on said support structure for pivoting said pivotarms about said axes from a closed disposition, wherein said pivot armsare parallel to each other and to said center-line along a first facingportion and then diverge slightly from one another at their distal entryends forming a gap therebetween due to the difference in diameter orwidth of said roller sections. to an open disposition wherein said pivotarms are diagonal to said centerline. and back again;

moving means mounted on each one of said pivot arms about said rollersections for providing moving contact surfaces on the inner sides ofsaid pivot arms, said moving contact surfaces being at least insubstantial part parallel and in opposing face-toface relationship toeach other when said pivot arms are parallel, although still thenpresenting a tapered or angular disposition at the entry roller section,and presenting a completely tapered or angular disposition when saidpivot arms are diagonal;

conveyor means for conveying the structures on a one-by-one basis intothe distal ends of said pivot arms removed from said axes; and

control means for actuating said drive means to dispose said pivot armsin their open disposition for entry of each structure and to disposesaid pivot arms in their closed disposition when each structure issubstantially into and between the open pivot arms; whereby. when saidpivot arms are driven to their closed disposition. the contact surfacesinitially contact the structure with point contact and then with fullline, face-to-face contact as the structure is conveyed through thein-feed device, and whereby, when the contact surfaces become parallelbetween said central and exit rollers when said pivot arms are parallel,the contact surfaces as they approach the central rollers do so with arelatively gradual taper.

10. The device of claim 9, wherein there is further in cluded:

1 1 v 1 2 opposed retarding pressure finger means mounted on straps foradjusting the physical location of the dis said distal entry endsprojecting inwardly toward tal, operative ends of said straps withrespect to said center-line and angularly back toward the saidcenter-line; whereby the retarding pressure of proximal ends of saidpivot arms for bearing against the straps can be varied or the strapsmoved away only the intermediate and end portions of the struc- 5 fromthe center-line to such an extent that the ture at points removed fromthe initial contact straps are rendered inoperative point of the movingsurfaces with the structure 12. The device of claim 9 wherein said drivemeans when said pivot arms are in their closed disposition comprise: forretarding the structure against the advancing a reciprocating yokelocated along the center-line of force of the contact surfaces incontact with the 10 the device having two slots therein which angularlystructure; whereby wrinkles in the material are diverge on oppositesides of said center-line, and eliminated or prevented from forming.wherein said pivot arms includes: 11. The device of claim 10 whereinsaid pressure finvertical pins which ride in said slots; whereby. germeans are made of straps of resilient, springy matewhen said yoke isreciprocated back and forth along rial and have inherent bias to moveaway from said censaid center-line, said pivot arms are caused to movetenline, and wherein there is further included: back and forth betweentheir closed and open disset screw adjusting means mounted on said pivotpositions.

arms and bearing against the operative ends of said

1. An in-feed device for a machine for structures comprised of facingsheets of flat, flexible material which need to be properly aligned forfurther processing, such as for example the top of a bag needing to beclosed, comprising: a basic machine support structure; two, opposed,elongated pivot arms pivotably mounted on said support structure forpivoting about axes which are located on opposite sides of, but inproximity to, the center-line of the machine; drive means mounted onsaid support structure for pivoting said pivot arms about said axes froma closed disposition wherein said pivot arms are parallel to saidcenterline to an open disposition wherein said pivot arms are diagonalto said center-line and back again; moving means mounted on each one ofsaid pivot arms for providing moving contact surfaces on the inner sidesof said pivot arms, said moving contact surfaces being at least insubstantial part parallel and in opposing face-to-face relationship toeach other when said pivot arms are parallel and presenting a tapered orangular disposition when said pivot arms are diagonal; conveyor meansfor conveying the structures on a one-by-one basis into the distal endsof said pivot arms removed from said axes; control means for actuatingsaid drive means to dispose said pivot arms in their open dispositionfor entry of each structure and to dispose said pivot arms in theirclosed disposition when each structure is substantially into and betweenthe open pivot arms; whereby, when said pivot arms are driven to theirclosed disposition, the contact surfaces initially contact the structurewith point contact and then will full line, face-to-face contact as thestructure is conveyed through the in-feed device; and opposed retardingpressure finger means mounted on said distal entry ends projectinginwardly toward said center-line and angularly back toward the proximalends of said pivot arms to a point intermediate to said distal and saidproximal ends for bearing against the structure only at points removedfrom the initial contact point of the moving surfaces with the structurewhen said pivot arms are in their closed disposition for retarding theimmediate and following portions of the structure against the advancingforce of the contact surfaces in contact with the structure; wherebywrinkles in the material are eliminated or prevented from forming. 2.The device of claim 1 wherein said pivot arms, when in their closeddisposition, are parallel to each other along a first facing portion andthen diverge slightly from one another at their distal entry endsforming a gap there between; thereby forming a tapered entry portioneven when said pivot arms are in their closed disposition.
 3. The deviceof claim 1 wherein said pressure finger means are made of straps ofresilient, springy material and have inherent bias to move away fromsaid center-line, and wherein there is further included: set screwadjusting means mounted on said pivot arms and bearing against theoperative ends of said straps for adjusting the physical location of thedistal, operative ends of said straps with respect to said center-line;whereby the retarding pressure of the straps can be varied or the strapsmoved away from the center-line to such an extent that the straps arerendered inoperative.
 4. The device of claim 1 wherein said movingcontact surfaces are belts, each one mounted on at least two rollersattached to the pivot arm.
 5. The device of claim 1 wherein there isincluded at least three rollers - an entry roller located toward thedistal end of each said pivot arms, a central roller located centrallyon each said pivot arms, and an exit roller located toward the proximalend of each said pivot arms, said entry roller having a diameter lessthan that of the other two rollers which are equal, whereby, when thecontact surfaces become parallel between said central and exit rollerswhen said pivot arms are parallel, the contact surfaces as they approachthe central rollers do so with a relatively gradual taper.
 6. The deviceof claim 1 wherein there is further included: bottom conveying meansassociated with said conveyor means for supporting and conveying thestructure through the in-feed device and into the next processingstation of the machine.
 7. The device of claim 1 wherein there isfurther included: a supplemental, opposed set of parallel, movingcontact surfaces mounted on supports which are fixed with respect to oneanother during operation and which bridge between the proximal ends ofsaid pivot arms and the next processing station of the machine, the exitportion of said moving belt means leading into said supplemental set ofmoving contact surfaces.
 8. The method of feeding structures on aone-by-one basis into a machine wherein the structures are comprised offacing sheets of flat, flexible material which need to be properlyaligned for further processing, such as for example the top of a bagneeding to be closed, comprising the following steps: a. providing anin-feed device having an inlet portion comprised of two movable, opposedsupport arms mounted on opposite sides of the center-line of the machineand carrying on their inward, opposed sides longitudinally movingcontact surfaces, and also carrying on their inward, opposed sidespressure finger means located at the distal, entry ends of said supportarms and projecting inwardly toward said center-line and angularly backtoward the proximal ends of said support arms to a point intermediate tosaid distal and said proximal ends, said support arms initially havingan open, angular disposition with respect to the center-line of themachine, and providing appropriate conveying means in association withsaid in-feed device; b. conveying the structures into the inlet portionof the in-feed device so that the leading edge of said structure is pastthe ends of said pressure fingers and the structure is substantiallyinto and between said opposed support arms; c. positively grasping theleading edge of the structure with the longitudinally moving contactsurfaces by moving the support structures angularly in from theirinitial, open, angular disposition and toward the center-line of themachine so that the contact surfaces initially strike the leading edgeof the structure at an angle with only opposed, point contacts, andclosing at least an opposed portion of the support structures togetherso that the moving contact surfaces come together after initiallystriking the structures changing the point contacts to continuing,face-to-face, in line and opposed contacts; d. conveying the structurethrough the in-feed device to the next processing station of themachine; and e. applying a retarding force on the structure by means ofsaid pressure finger means bearing against only the intermediateportions, at an area located between the distal and proximal ends ofsaid support arms, and subsequentially the trailing edges of thestructure in a direction opposite to the advancing action of theconveying means while the structure is being conveyed through thein-feed device; whereby wrinkles are removed from, or prevented fromforming in, the material.
 9. An in-feed device for a machine forstructures comprised of facing sheets of flat, flexible material whichneed to be properly aligned for further processing, such as for examplethe top of a bag needing to be closed, comprising: a basic machinesupport structure; two, opposed, elongated pivot arms pivotably mountedon said support structure for pivoting about axes which are located onopposite sides of, but in proximity to, the center-line of the machine,each said pivot arms including at least three roller sections, an entryroller section located toward the distal end of each said pivotal arms,a central roller section located centrally on each said pivot arms, andan exit roller section located toward the proximal end of each saidpivot arms, said entry roller section having a diameter or width lessthan that of the other two roller sections which are equal; drive meansmounted on said support structure for pivoting said pivot arms aboutsaid axes from a closed disposition, wherein said pivot arms areparallel to each other and to said center-line along a first facingportion and then diverge slightly from one another at their distal entryends forming a gap therebetween due to the difference in diameter orwidth of said roller sections, to an open disposition wherein said pivotarms are diagonal to said center-line, and back again; moving meansmounted on each one of said pivot arms about said roller sections forproviding moving contact surfaces on the inner sides of said pivot arms,said moving contact surfaces being at least in substantial part paralleland in opposing face-to-face relationship to each other when said pivotarms are parallel, although still then presenting a tapered or angulardisposition at the entry roller section, and presenting a completelytapered or angular disposition when said pivot arms are diagonal;conveyor means for conveying the structures on a one-by-one basis intothe distal ends of said pivot arms removed from said axes; and controlmeans for actuating said drive means to dispose said pivot arms in theiropen disposition for entry of each structure and to dispose said pivotarms in their closed disposition when each structure is substantiallyinto and between the open pivot arms; whereby, when said pivot arms aredriven to their closed disposition, the contact surfaces initiallycontact the structure with point contact and then with full line,face-to-face contact as the structure is conveyed through the in-feeddevice, and whereby, when the contact surfaces become parallel betweensaid central and exit rollers when said pivot arms are parallel, thecontact surfaces as they approach the central rollers do so with arelatively gradual taper.
 10. The device of claim 9, wherein there isfurther included: opposed retarding pressure finger means mounted onsaid distal entry ends projecting inwardly toward said center-line andangularly back toward the proximal ends of said pivot arms for bearingagainst only the intermediate and end portions of the structure atpoints removed from the initial contact point of the moving surfaceswith the structure when said pivot arms are in their closed dispositionfor retarding the structure against the advancing force of the contactsurfaces in contact with the structure; whereby wrinkles in the materialare eliminated or prevented from forming.
 11. The device of claim 10wherein said pressure finger means are made of straps of resilient,springy material and have inherent bias to move away from saidcenter-line, and wherein there is further included: set screw adjustingmeans mounted on said pivot arms and bearing against the operative endsof said straps for adjusting the physical location of the distal,operative ends of said straps with respect to said center-line; wherebythe retarding pressure of the straps can be varied or the straps movedaway from the center-line to such an extent that the straps are renderedinoperative.
 12. The device of claim 9 wherein said drive meanscomprise: a reciprocating yoke located along the center-line of thedevice having two slots therein which angularly diverge on oppositesides of said center-line, and wherein said pivot arms includes:vertical pins which ride in said slots; whereby, when said yoke isreciprocated back and forth along said center-line, said pivot arms arecaused to move back and forth between their closed and opendispositions.